The present invention relates to the use of silica powder as dispersing agent and filler with antifungal drugs for the treatment of fungal infection of the skin. The present invention further relates to a method to manufacture an antifungal powder.
Most drugs currently available for the treatment of mycoses have limited efficacy, because they are used in low concentration owing to their high toxicity. Their beneficial effects, depends in the vehicle used.
Prior art formulations of fungicides used as carrier or diluent, liquid suspension, ointment, cataplasm, liniment, lotion
Mycoses (e.g., athlete's foot) is a skin fungal infection that primarily occurs at moist parts of the body. So, when cream, gel or ointment preparations is applied to the affected part, it makes the affected part even more moist.
To avoid the skin moisture it is convenient that the preparation be in powder form. Prior art formulations in powder form used starch, talc, alum, borate as a vehicle.
U.S. Pat. No. 992,937 describes a nursery powder that combines boric acid with talcum powder as a vehicle
U.S. Pat. No. 2,289,125 describes a combination of boric acid and tannic acid used in powder form with corn starch as filler for the treatment of fungus infection.
U.S. Pat. No. 4,816,254 describes another combination of boric acid and used in form of ointment,
U.S. Pat. No. 4,935,241 describes a pharmaceutical preparation for tinea pedis with croconazole hydrochloride and a copolymer in an aqueous alcohol vehicle.
U.S. Pat. No. 5,711,954 describes an antifungal powder composition using imidazole compound in combination with talc coated with a hydrophobic coating.
In U.S. Pat. No. 5,994,403 a liquid solution of tannic acid is used for the treatment of fungal skin infections
In U.S. Pat. No. 6,399,108 boric acid is used in combination with borate salt.
Starch may be avoided because it feeds any bacteria or fungi that may be present
Talc or talcum powder is a hydrous magnesium silicate, with alkaline impurities, sticks to the skin, and keeps the skin moisturized. With certain imidazole compounds, show significant degradation of the active ingredient during storage.
Alum is a potassium or ammonium aluminum sulfate, and has alkaline molecules that favors fungus grow.
Borate salt, sodium tetraborate is alkaline.